Tuesday, December 25, 2012

Don’t neglect your windscreen wipers

Motorists change their engine oil and top up their battery water regularly. Yet how many bother to check their windscreen wipers? Not many. Often, wiper blades that are cracked, torn, brittle are still used nonchalantly without regard to the possible risks they pose.

The importance of effective windscreen wipers cannot be over-stressed. Wipers keep your windscreen clear of rain and road splash that may obstruct your vision. Even though wipers are not used daily, their average life span is about six months to one year.

Wiper blades may not be able to function properly because of several reasons, one of which is prolonged exposure to the elements. After having been exposed to the sun for long periods, the wiper blades may have come curved permanently and are unable to make full contact with the windscreen. Another reason is wear and tear on the edges of the wiper blades.

When the blade loses its edge, water gets under the blade and remains there. How a windscreen wiper performs also depends on the amount of spring tension on the wiper arms, the number of claws that hold the blade, and the design of the blade itself. Weak springs may fail to press the blade firmly enough on the windscreen for the former to wipe cleanly.

When the car is travelling at high speed, wind lift can also affect the wiping action of the blades. Compared to a regular windscreen, a steeply sloped windscreen with a larger glass area directs more wind against the wipers. The wind may lift the blades away from the glass unless they have been designed to counteract thermodynamic forces. Anti-wind lift design usually features vents and air-foils to cut lift and generate down force to hold the blade in constant contact with the windscreen as speed increases.

The design of the blade holder can also have a bearing on wiper operation. The function
of the blade holder is to distribute the tension of the wiper arm evenly over the blade while also allowing the blade to flex as it follows the curvature of the windscreen. Good blade holders have six claws to eight claws to distribute the pressure of the wiper arm over the blade.

So, how do you maintain your wiper blades? Check them at least once every four months or when they don't seem to function as effectively as before. Tree sap and hot wax treatments by automatic car wash can affect their effectiveness. Check that the pivot points of the wiper arms move freely. Apply oil to lubricate the pivot points if necessary. The wiper blades and windscreen should be cleaned with windshield wiper solution or mild detergent.


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